How can it be a crap shoot when the odds at the top are higher than the odds at the bottom? A crap shoot would be if every position in the draft had the same odds of landing an all star. Or if the draft position was decided by random chance with no odds being better whether you're the worst team in the league or the champions.
The worst team in the league has the best odds of landing the #1 pick. Doesn't mean it's going to land the #1 pick every time but way more often than not, they're going to go #1. If it was a crap shoot, the NBA wouldn't put more balls for that team in the machine than the 2nd and 3rd place teams. They would be equal.
The draft is the same. The #1 pick has a higher chance of being an all star than the #5 pick. That's not a crap shoot nor random chance. That's playing the odds. You could possibly pick at 5 and beat my pick at 1 but if we played long enough, I'm guaranteed to beat you because I'll wind up having the bigger collection of better picks due to the odds of it.
http://www.82games.com/nbadraftpicks.htm
I couldn't find the actual percentages but here are some statistics based on draft positioning. It's not perfectly linear due to the fact that like you said, you can get good players outside of the top few picks but if you graphed it out, the graph would slope downward. If there was a crap shoot, the numbers would look basically the same for each position and the graph wouldn't have a slant to it. You have to play the odds here. The argument isn't that we can't land a good player further down the draft, it's that we have a better chance of landing one at the top. Just look at the drop off after the top 5. I want the odds in the top 5, not down in the teens.